Structure and method for joining extruded members

Abstract: 1. A joint structure including an extrudate member and a rod-like mating member, in which the extrudate member has a closed sectional structure portion and has an end thereof joined to the rod-like mating member such that the extrudate member intersects a longitudinal direction of the rod-like mating member. The extrudate member includes a joint portion integrally provided at an end thereof and adapted to be matched to the shape of an outer surface of the mating member to wrap the mating member. The joint portion is bonded to the outer surface of the mating member at its longitudinally intermediate portion by a brazing, a spot-welding or the like.

Description: The present invention relates to a structure for joining an extrudate member and a mating member together, and particularly, to an improvement in a structure and a method for joining an extrudate member having a closed sectional structure portion and a mating rod member while placing an end of the extrudate member so as to intersect the mating member. In the prior art joining structure of this type, a butt welding joint or a joint member has been utilized at a junction between the extrudate member and the mating member. However, if the butt welding joint is employed, a preselected joining jig is required and hence, the handling of the jig is troublesome, resulting in a degraded joining operability. Further, if the joint member is employed, the number of parts is correspondingly increased, and the construction is complicated. EP-A-0547346 discloses an extruded suspension component joined to an elongate mating member. This document discloses a joint structure comprising: an extrudate member (the suspension component) having a closed sectional structure portion and an integral joining region; and an elongated mating member having a longitudinal axis; the joining region including a joint portion having a shape conformed to a shape of an outer surface of said elongated mating member so as to encircle at least a portion of said mating member, said joint portion being joined to the outer peripheral surface of said mating member. In the structure of EP-A-0547346, the longitudinal axes of the extrudate member and the elongate mating member are parallel, the joint portion being created by the extrusion process by which the extrudate member is formed. It is not possible to use such a structure if the longitudinal axes of the extrudate member and the elongate mating member are to intersect. The joint structure of the preamble of claim 1 is shown in EP-A-0078551. According to one aspect of the present invention, the closed sectional structure portion of said extrudate member has a polygonal cross-section and the joint portion is formed by an extension of at least one side of said polygonal-shaped closed sectional structure portion. In this joint structure, no separate joint member is used, leading to a simplified construction. In addition, since the joint portion is joined to the mating member in a state where the joint portion is matched to the outer surface of the mating member so as to encircle the latter, the structure has a high joining strength. According to another aspect of the present invention, there is provided a method for joining an extrudate member and an elongated mating member, in which said extrudate member has a closed sectional structure portion and an integral joining end for joining to said elongated mating member characterized in that the method comprises the steps of: forming a notch in the integral joining end of the closed sectional structure portion of said extrudate member so as to extend longitudinally of the extrudate member subjecting a portion of the extrudate member around said notch to plastic working to provide a joint portion having a shape conformed to the shape of an outer surface of said mating member so as to encircle at least a portion of said mating member; and joining said joint portion to said outer surface of said mating member such that the longitudinal axis of said extrudate member intersects the longitudinal axis of said elongated mating member. In the above joining method, by matching the joint portion to the outer surface of the mating member, the positioning of the extrudate member relative to the mating member can be achieved and hence, a joining jig is not required, leading to an improved joining operatability. For a better understanding of the present invention and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which:- Fig. 1 is a perspective view of one example of an extrudate member; Fig. 2 is a cutaway perspective view of an essential portion of one example of a mating member; Fig.3 is a perspective view of an extrudate member having a notch defined therein; Fig.4 is a perspective view of an extrudate member having a joint portion; Fig.5 is a plan view of the extrudate member having the joint portion; Fig.6 is a perspective view of the extrudate member and a mating member shown as being assembled to each other; Fig.7 is a sectional view taken along a line 7-7 in Fig.6; Fig.8 is a perspective view of another example of an extrudate member; Fig.9 is a cutaway perspective view of an essential portion of another example of a mating member; Fig.10 is a perspective view of an extrudate member with notches defined therein; Fig.11 is a perspective view of an extrudate member having a joint portion; Fig.12 is a perspective view of the extrudate member and a mating member shown as being assembled to each other; Fig.13 is a sectional view taken along a line 13-13 in Fig.12; and Fig.14 is a diagrammatic perspective illustration of a frame structure for a vehicle body. Figs.1 to 7 illustrate a first embodiment of the present invention. Referring to Fig.1, an extrudate member A 1 is formed from an aluminum alloy and includes a closed sectional structure portion a 1 having a dovetailed annular section. This closed sectional structure portion a 1 comprises a first flat portion 3, a second flat portion 4 opposed to and shorter than the first flat portion 3, a first inclined portion 5 interconnecting opposing first side edges of the first and second flat portions 3 and 4, and a second inclined portion 6 interconnecting opposing second side edges of the first and second flat portions 3 and 4. Overhangs 7 and 8 are provided on opposite side edges of the first flat portion 3 of the closed sectional structure portion a 1 , such that they are located on the same plane as the first flat portion 3. Referring to Fig.2, a mating member B 1 for the extrudate member A 1 is produced using an aluminum alloy material, as is the extrudate member A 1 . The mating member B 1 includes a closed sectional structure portion b 1 having a dovetailed annular section. This closed sectional structure portion b 1 comprises a first flat portion 9, a second flat portion 10 opposed to and shorter than the first flat portion 9, a first inclined portion 11 interconnecting opposing first side edges of the first and second flat portions 9 and 10, and a second inclined portion 12 interconnecting opposing second side edges of the first and second flat portions 9 and 10. An overhang 13 is provided on one of the side edges of the first flat portion 9 of the closed sectional structure portion b 1 , such that it is located on the same plane as the first flat portion 9. And an overhang 14 having a hook-like section is provided on the other side edge of the first flat portion 9. The first inclined portion 11 is formed flat, while the second inclined portion 12 is formed in a stepped manner and has an engaging groove 15 1 in its outer surface to extend along the side edge of the second flat portion 10. In order to joint an end of the extrudate member A 1 having the closed sectional structure portion a 1 to a longitudinally intermediate portion of the mating member B 1 such that they extend across each other, following steps are carried out in sequence: (a) As shown in Fig.3, the first flat portion 3 of the closed sectional structure portion a 1 is cut off partially at the end of the extrudate member A 1 to define a notch 16 1 extending along the longitudinal axis of the extrudate member A 1 . (b) As shown in Figs.4 and 5, a portion of the extrudate member A 1 around the notch 16 1 is subjected to a bending including a development as a plastic working thereby to form a joing portion c 1 . The joint portion c 1 is formed into a shape conforming to a profile of an outer surface of the mating member B 1 , e.g., a shape of an outer surface area extending from the flat overhand 13 via the first inclined portion 11 and the second flat portion 10 to the engage groove 15 1 of the second inclined portion 12 in this embodiment, so as to encircle a portion of the mating member B 1 . The joint portion c 1 is formed out of portions of the first flat portion 3 and the overhangs 7 and 8. More particularly, the joint portion c 1 includes a first planar portion 17 corresponding to the flat overhang 13 of the mating member B 1 , a first slope portion 19 which is continuously formed with the first planar portion 17 and divided into two by a dovetailed hole 18 and which corresponds to the first inclined portion 11 of the mating member B 1 , a second planar portion 20 continuously formed with the first slope portion 19 and the second flat portion 4 and corresponding to the second flat portion 10 of the mating member B 1 , a second slope portion 21 continuously formed with the second planar portion 20 and corresponding to a portion of the second inclined portion 12, and an engaging claw 22 1 continuously formed with the second slope portion 21 and corresponding to the engaging groove 15 1 .As is best shown in Fig. 5, the length of the joint portion c 1 in a direction intersecting the longitudinal axis of the extrudate member A 1 at right angles, i.e., the width d 1 (maximum width) of the joint portion c 1 larger than the width e 1 of the extrudate member A 1 in the same direction (d 1 > e 1 ). (c) As is shown in Figs.6 and 7, at the joint portion c 1 and a longitudinally intermediate portion of the mating member B 1 , the first planar portion 17 and the flat overhang 13 are matched to each other; the first slope portion 19 and the first inclined portion 11 are matched to each other; the second planar portion 20 and the second flat portion 10 are matched to each other, and the second slope portion 21 and the second inclined portion 12 are matched to each other. In addition, the engaging claw 22 1 is brought into engagement with the engaging groove 15 1 . This provides a wrapping-in or encircling effect by the joint portion c 1 , and a latching effect by the engaging groove 15 1 and the engaging claw 22 1 and thus, the extrudate member A 1 and the mating member B 1 are assembled integrally. (d) The superposed portions of the first planar portion 17 and the flat overhang 13 and the like, are bonded to each other by a bonding means such as a spot-welding, brazing or the like. In the joining structure, the extrudate member A 1 is integrally provided at one end thereof with the joint portion c 1 having the shape conformed to the shape of the outer surface of the mating member B 1 to encircle a portion of the mating member B 1 . The joint portion c 1 is joined to the outer surface of the longitudinal intermediate portion of the mating member B 1 and hence, no separate joint member is used. Therefore, the construction of the joining structure is simplified. In addition, the joint portion c 1 is joined to the longitudinally intermediate portion of the mating member B 1 in such a manner that it is matched to the outer surface of the longitudinally intermediate portion of the mating member B 1 over the relatively large width d 1 to encircle a portion of the mating member B 1 , and therefore, the joining structure has a high joining strength. On the other hand, in the joining method, by matching joint portion c 1 to the outer surface of the mating member B 1 and bringing the engaging claw 22 1 into engagement with the engaging groove 15 1 , the positioning of the extrudate member A 1 relative to the mating member B 1 can be achieved. Therefore, a joining jig is not required, leading to a good operatability. Figs.8 to 13 illustrate a second embodiment of the present invention. Referring to Fig.8, an extrudate member A 2 is formed from an aluminum alloy and has a substantially square annular section. Therefore, the extrudate member A 2 comprises only a closed sectional structure portion a 2 including two sets of opposed sidewall portions 23, 24 and 25, 26. Referring to Fig.9, a mating member B 2 for the extrudate member A 2 is produced by an extrusion using an aluminum alloy material, as is the extrudate member A 2 . The mating member B 2 comprises a pair of opposed flat portions 27 and 28, and a pair of arcuate portions 29 and 30 interconnecting two pairs of opposing side edges of the flat portions 27 and 28, respectively, and thus, the mating member M 1 is comprised of only a closed sectional structure portion b 2 . A pair of egnaging grooves 15 2 are defined in an outer surface of one of the arcuate portions 30 to extend longitudinally of the arcuate portion 30. In order to joint an end of the extrudate member A 2 having the closed sectional structure portion a 2 to a longitudinally intermediate portion of the mating member B 2 such that they extend across each other, following steps are carried out in sequence: (a) As shown in Fig.10, portions of the opposed sidewalls 23 and 24 are cut off at the end of the extrudate member A 2 to define a pair of notches 16 2 extending longitudinally of the extrudate member. In this case, an inner end face of each notch 16 2 is formed into an arcuate shape to conform to a shape of an outer surface of the arcuate portion 29 having no engaging groove 15 2 in the mating member B 2 . (b) As shown in Fig.11, portions around the notches 16 2 of the extrudate member A 2 , e.g., tip ends of opposed sidewalls 25 and 26 of the notches 16 2 in this embodiment, are subjected to a bending as a plastic working, thereby producing a joint portion c 2 . The joint portion c 2 is formed to have a shape conformed to the shape of the outer surface of the mating member B 2 , e.g., the shape of an outer surface area extending from one of the engaging grooves 15 2 via one of the arcuate portions 29 and the other flat portion 28 to the other engaging groove 15 2 in this embodiment to encircle a portion of the mating member B 2 . More particularly, the joint portion c 2 comprises a planar portion 32 corresponding to one of the flat portions 27 of the mating member B 2 , arcuate portions 33 which are continuously formed with the planar portion 32 and formed of portions of opposite sidewalls 23 and 24 and which correspond to one of the arcuate portions 29 of the mating member B 2 , a planar portion 34 continuously formed with the arcuate portions 33 and corresponding to the other flat portion 28 of the mating member B 2 , arcuate portions 35 continuously formed with the planar portions 32 and 34 and corresponding to a portion of the other arcuate portion 30 of the mating member B 2 , and engaging claws 22 2 continuously formed with the arcuate portions 35 and corresponding to the engaging grooves 15 2 of the mating member B 2 .In this case, the length of the joint portion c 2 in a direction intersecting the longitudinal axis of the extrudate member A 2 at right angles, i.e., the width d 2 thereof, is equal to the width e 2 of the extrudate member A 2 in the same direction ( d 2 = e 2 ). (c) As shown in Figs. 12 and 13, at the joint portion c 2 and a longitudinally intermediate portion of the mating member B 2 , the one planar portion 32 and the one flat portion 27 are matched to each other; the other planar portion 34 and the other flat portion 28 are matched to each other; the arcuate portions 33 and the one arcuate portion 29 are matched to each other; and the arcuate portions 35 and the other arcuate portion 30 are matched to each other. In addition, each of the engaging claws 22 2 is brought into engagement with corresponding one of the engaging grooves 15 2 . This provides an encircling effect by the joint portion c 2 , and a latching effect by each of the engaging grooves 15 2 and each of the engaging claws 22 2 , and thus, the extrudate member A 2 and the mating member B 2 are assembled into one piece. (d) The superposed portions of the one planar portion 32 and the one flat portion 27 and the like, are bonded to each other by a bonding means such as a spot-welding, brazing or the like. With the joint structure and the joining method of the second embodiment, effects similar to those of the first embodiment can be provided. Alternatively, engaging grooves 15 1 and 15 2 may be provided in the joint portions c 1 and c 2 , and engaging claws 22 1 and 22 2 may be provided on the mating members B 1 and B 2 . Fig. 14 illustrates a frame structure for a vehicle body. The present invention is applicable to the structure and method for joining, for example, a front roof rail 37 which is an extrudate member of an aluminium alloy, and a front pillar 38 which is an extrudate member

Claims: A joint structure comprising: an extrudate member (A 1 , A 2 ) having a closed sectional structure portion and an integral joining region; and an elongate mating member (B 1 , B 2 ) having a longitudinal axis; the joining region including a joint portion (C 1 , C 2 ) having a shape conformed to a shape of an outer surface of said elongated mating member (B 1 , B 2 ) so as to encircle at least a portion of said mating member (B 1 , B 2 ), said joint portion (C 1 , C 2 ) being joined to the outer peripheral surface of said mating member (B 1 , B 2 ) and being situated at a longitudinal end of the extrudate member (A 1 , A 2 ), the longitudinal axis of the extrudate member (A 1 , A 2 ) intersecting the longitudinal axis of the mating member (B 1 , B 2 ), characterized in that the closed sectional structure portion of said extrudate member (A 1 , A 2 ) has a polygonal cross-section and in that the joint portion (C 1 , C 2 ) is formed by an extension (20, 32, 34) of at least one side of said polygonal-shaped closed sectional structure portion. A joint structure as claimed in claim 1, characterized in that one of said joint portion (C 1 , C 2 ) and said elongated mating member (B 1 , B 2 ) has an engaging groove (15 1 , 15 2 ), and the other has an engaging claw (22 1 , 22 2 ) for engagement with said engaging groove (15 1 , 15 2 ). A joint structure as claimed in claim 1 or 2, characterized in that said elongated mating member (B 1 ) includes a closed sectional structure portion having a substantially dovetailed annular section, said closed sectional structure portion of the mating member including, (a) a first flat portion (9), (b) a second flat portion (10) opposed to and shorter than said first flat portion (9), (c) a first inclined portion (11) interconnecting opposing first side edges of the first and second flat portions (9, 10), and (d) a second inclined portion (12) interconnecting opposing second side edges of the first and second flat portions (9, 10) and having an engaging groove (15 1 ) provided on an outer surface thereof to extend along the side edge of the second flat portion (10); and wherein said joint portion (C 1 ) includes: (e) a first slope portion (19) matched to the first inclined portion (11) of said mating member (B 1 ), (f) a second planar portion (20) continuously formed with said first slope portion (19) and matched to the second flat portion (10) of said mating member (B 1 ). (g) a second slope portion (21) continuously formed with said second planar portion (20) and matched to a portion of the second inclined portion (12) of said mating member (B 1 ), and (h) an engaging claw (22 1 ) continuously formed with said second slope portion (21) and engaged with the engaging groove (15 1 ) in said mating member (B 1 ). A joint structure as claimed in claim 3, characterized in that the length (d 1 ) of said joint portion (C 1 ) in a direction intersecting the longitudinal axis of said extrudate member (A 1 ) is longer than the length (e 1 ) of the extrudate member (B 1 ) in the same direction. A joint structure as claimed in claim 1, characterized in that said elongated mating member (B 2 ) includes, a closed sectional structure portion which is comprised of: (a) a pair of opposed flat portions (27, 28), and (b) a pair of arcuate portions (29, 30) interconnecting opposed side edges of said flat portions (27, 28), respectively, one (30) of said arcuate portions being formed with a pair of engagement grooves (15 2 ) on an outer surface thereof so as to extend longitudinally of said arcuate portion (30), and wherein said joint portion includes: (c) one planar portion (32) matched to one (27) of said flat portions of said elongated mating member (B 2 ), (d) arcuate portions (31) continuously formed with said one planar portion (32) and matched to one (29) of said arcuate portions of said elongated mating member (B 2 ), (e) another planar portion (34) continuously formed with said arcuate portions (31) and matched to the other flat portion (28) of said elongated mating member (B 2 ), (f) further arcuate portions (35) continuously formed with said respective planar portions (32, 34) and matched to a portion of the other arcuate portion (30) of said elongated mating member (B 2 ), and (g) engaging claws (22 2 ) continuously formed with said further arcuate portions (35), respectively, and matched to the engaging grooves (15 2 ) of the elongated mating member (B 2 ), respectively. A joint structure as claimed in any one of the preceding claims, characterized in that each of said extrudate member (A 1 , A 2 ) and said mating member (B 1 , B 2 ) is formed from an aluminum alloy, and said mating member (B 1 , B 2 ) is also produced by extrusion. A joining structure as claimed in any one of the preceding claims, characterized in that said extrudate member (A 1 , A 2 ) is a hollow member which has been obtained by extrusion conducted in a direction aligned with the longitudinal axis of the extrudate member (A 1 , A 2 ), and said joint portions (C 1 , C 2 ) is obtained by subjecting said integral joining end of the extrudate member to a plastic working. A joint structure as claimed in any one of the preceding claims, characterized in that said joint portion (C 1 , C 2 ) encircles said portion of the mating member (B 1 , B 2 ) in the extruding direction of the extrudate member (A 1 , A 2 ). A method for joining an extrudate member (A 1 , A 2 ) and an elongated mating member (B 1 , B 2 ), in which said extrudate member (A 1 , A 2 ) has a closed sectional structure portion and an integral joining end for joining to said elongated mating member (B 1 , B 2 ) characterized in that the method comprises the steps of: forming a notch (16 1 , 16 2 ) in the integral joining end of the closed sectional structure portion of said extrudate member (A 1 , A 2 ) so as to extend longitudinally of the extrudate member (A 1 , A 2 ); subjecting a portion of the extrudate member (A 1 , A 2 ) around said notch (16 1 , 16 2 ) to plastic working to provide a joint portion (C 1 , C 2 ) having a shape conformed to the shape of an outer surface of said mating member (B 1 , B 2 ) so as to encircle at least a portion of said mating member (B 1 , B 2 ); and joining said joint portion (C 1 , C 2 ) to said outer surface of said mating member (B 1 , B 2 ) such that the longitudinal axis of said extrudate member (A 1 , A 2 ) intersects the longitudinal axis of said elongated mating member (B 1 , B 2 ). A method as claimed in claim 9, characterized in that said joining is achieved by engagement between an engaging groove (15 1 , 15 2 ) provided on one of said joint portions (C 1 , C 2 ) and said mating member (B 1 , B 2 ) and an engaging claw (22 1 , 22 2 ) provided on the other. A joint structure as claimed in claim 1, wherein said elongate mating member (B 1 , B 2 ) has a polygonal cross-section with at least one side thereof being engaged with said joint portion (C 1 , C 2 ) of the extrudate member (A 1 , A 2 ).

Inventors: FUJITA SHIGEO, SATO MASAKAZU, YOSHIDA SUGURA, FUJITA, SHIGEO, SATO, MASAKAZU, YOSHIDA, SUGURU, FUJITA, SHIGEO, C/O KABUSHIKI KAISHA HONDA, SATO, MASAKAZU, C/O KABUSHIKI KAISHA HONDA, YOSHIDA, SUGURA, C/O KABUSHIKI KAISHA HONDA
Applicants: HONDA MOTOR CO LTD, HONDA GIKEN KOGYO KABUSHIKI KAISHA
Application year: 1994
Main classification: B62D29
IPC codes: B21D53, B23K33, B62D27, B62D23, B62D29, B21D39, B21D51, B21C23